@import url('https://fonts.googleapis.com/css?family=poppins:100,200,300,400,500,600,700');

body {
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: #333;
    font-family: 'Poppins', sans-serif;
}

ul {
    margin: 0;
    padding: 0;
    display: flex;
}

ul li {
    position: relative;
    list-style: none;
    width: 20px;
    height: 20px;
    background: #777;
    margin: 0 20px;
    border-radius: 50%;
    transition: 0.5s;
    cursor: pointer;
}

ul li:hover {
    background: #86ff3b;
    box-shadow: 0 0 0 4px #333,
                0 0 0 6px #86ff3b;
}

ul li .content {
    position: absolute;
    bottom: 55px;
    width: 400px;
    background: #fff;
    padding: 20px;
    box-sizing: border-box;
    border-radius: 4px;
    visibility: hidden;
    opacity: 0;
    transition: 0.5s;
    transform: translateX(-50%) translateY(-50px);
}

ul li .content:before {
    content: '';
    position: absolute;
    width: 30px;
    height: 30px;
    background: #fff;
    bottom: -15px;
    left: 194px;
    transform: rotate(45deg);
}

ul li:hover .content {
    visibility: visible;
    opacity: 1;
    transform: translateX(-50%) translateY(0px);
}

ul li .content h2 {
    margin: 0;
    padding: 0;
}
